1. Field of the Invention
The present invention is directed to the field of detecting open circuits in electrical loads and more specifically to the area of lamp failure detection systems for use on automotive vehicles.
2. Summary of the Invention
The present invention is related to our copending U.S. application Ser. No. 817,224, titled "A LAMP FAILURE MONITORING SYSTEM" that is being filed concurrently herewith. In the present invention, a toroidal core transformer is employed to sense the initial current flow through a conductor connected to a single electrical load (filament lamp) when energized through a switching means. The output pulse provided across the toroidal core transformer is provided through a logic network. A sensing circuit monitors the switching device and provides an enabling signal to the logic network whenever the switching device is closed. In the absence of a pulse being sensed across the toroidal transformer, the logic network provides an output signal to an indicator means. The absence of such a pulse would indicate that the series circuit of the load from the switching means is opened. The latched output of the logic network is connected to a circuit that provides a continuous indication of the failure detection.